Danger! High Voltage!

[97SpecialK]

First and foremost, I must say, this forum is excellent. Now, for my first ever post, I'm looking to you guys for some help. When I bought my 97 K1500 / 5.7L / Auto / 4x4 I noticed a little headlight and interior lighting flicker at night, only at idle. Not much so I ignored it, figuring I'd replace the alternator eventually since it has an internal VR. Now, here we are 10 months and a brand new engine later, and the flicker got way worse, still only at idle. Additionally, I noticed the volt gauge reading around 15v to 15.5v. I'm not entirely positive that this just started, although I think I would have noticed it as I'm usually pretty attentive with my gauges. So, assuming that was a new thing, I figured the VR was about to have a catastrophic meltdown and leave me stranded so, at my first opportunity, I replaced it with a brand new AC Delco OEM series alternator. I was right about the flickering, the new alternator cleared that right up. What has me scratching my head, however, is that the volt gauge still reads between 15v and 15.5v. Stranger still is that the volts will eventually settle down right at 14.5v after the truck has been running a while. I was hoping someone on here might have some insight on this. Maybe it's totally normal behavior and I'm not as good of an amateur mechanic as I think I am. Any input is appreciated.

 

[popcorn501]

Hook up a volt meter at the battery and see what it is really charging. One thing ive found over the years with my 98 K1500 is the gauges are not very accurate.

 

[97SpecialK]

Yeah that was my next planned step to see if I'm even getting accurate information. I'll get that done Monday when I get a new meter as mine has mysteriously disappeared. In the mean time, assuming my gauge is accurate-ish, has anyone ever heard of something like this and do you think I'm going to burn anything up running at up to 15.5v?

 

[jkeaton]

Fuses will take care of it.

 

[SAATR]

Fuses are there to protect against excessive current loads, not voltage. You could hit 24V and not burn the fuses, as long as the amperage is below its rating. Check your voltage at the alternator and see what output is, as has been suggested.

As for the flicker, I would suspect a potential ground issue. They cause a lot of crazy electrical behavior, and barring any other known issues, is one of the first places I would look.


Sent from my XT1585 using Tapatalk

 

[97SpecialK]

Ok I finally got a multimeter on the beast and it reads 15.2v when cold and then 14.7 when warmed up. Still seems odd to me that it would change like this but I'm comfortable with those numbers.

 

[laidbackbigun]

Most modern auto electronics can handle 16volts but not for extended periods. Being the truck isn't modern i would be wary very wary or running that voltage constantly. but damn i wish mine would run that high when my compressors or system is on. ha.